Natural organic matter quantification in the waters of a semiarid freshwater wetland (Tablas de Daimiel, Spain)

作     者：Montserrat Filella Juan Carlos Rodríguez-Murillo Franc ois Quentel 

作者机构：Institute F.-A. Forel University of Geneva10 route de SuisseCH-1290 Versoix Switzerland Museo Nacional de Ciencias Naturales CSICSerrano 115 E-28006 MadridSpain Laboratoire de Chimie Analytique UMR-CNRS 6521 Universit de Bretagne Occidentale6 avenue V.Le GorgeuCS 93837F-29238 Brest Cedex 3France 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2013年第25卷第1期

页      面：114-123页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 083001[工学-环境科学] 08[工学] 

主　　题：organic carbon natural organic matter refractory organic matter DOC ROM humic wetland Daimiel 

摘      要：Dissolved organic matter （DOM） concentrations have been measured in the waters of a semiarid freshwater wetland, the Tablas de Daimiel, Spain, when the system-characterised by variable hydroperiodicity conditions, was completely flooded （February 2011）. Fluxes of DOM from the wetland soils to the overlying waters were measured by using a passive diffusion sampler （peeper）. Not only dissolved organic carbon （DOC） concentrations were measured but refractory organic matter （ROM, usually known as humic substances） was also quantified using a novel voltammetric method. Fluorescence spectra were recorded to help in selecting the appropriate standard for ROM quantification, test the homogeneity of DOM in the waters and get an indication of their source. The results obtained show a 7-fold increase in measured ROM concentrations from the Gigtiela River to the outlet, which points to a net exportation of ROM from the wetland and to the existence of an internal source of ROM in the system, probably diffusion from the wetland soils. This hypothesis is confirmed by the flux of ROM from the soils to the water column measured with the peeper and by the common fluorescence characteristics of colunm and interstitial waters. The smaller increase in DOC concentrations along the wetland, in spite of the higher DOC fluxes from soils, suggests that there is significant turnover of organic carbon （OC） in the water column. The system acts as a major carbon sink but, when flooded, exports .OC as DOM.